Polymyxins are commonly used as the last resort for the treatment of MDR Acinetobacter baumannii and Klebsiella pneumoniae nosocomial infections; however, apart from the already known toxicity issues, resistance to these agents is emerging. In the present study, we assessed the in vitro synergistic activity of antimicrobial combinations against carbapenem-resistant and colistin-resistant A. baumannii and K. pneumoniae in an effort to provide more options for their treatment. Two hundred A. baumannii and one hundred and six K. pneumoniae single clinical isolates with resistance to carbapenems and colistin, recovered between 1 January 2021 and 31 July 2022,were included. A. baumannii were tested by the MIC test strip fixed-ratio method for combinations of colistin with either meropenem or rifampicin or daptomycin. K. pneumoniae were tested for the combinations of colistin with meropenem and ceftazidime/avibactam with aztreonam. Synergy was observed at: 98.99% for colistin and meropenem against A. baumannii; 91.52% for colistin and rifampicin; and 100% for colistin and daptomycin. Synergy was also observed at: 73.56% for colistin and meropenem against K. pneumoniae and; and 93% for ceftazidime/avibactam with aztreonam. The tested antimicrobial combinations presented high synergy rates, rendering them valuable options against A. baumannii and K. pneumoniae infections.

Over the past years, Acinetobacter baumannii has emerged as a serious nosocomial pathogen especially due to its extensively resistant antimicrobial profile

Background and Objectives: Thrombophilia is a prothrombotic disorder that increases the risk of blood clotting and can pose serious health problems. It is considered a condition of gene–gene or gene–environment interactions. Variation in the prevalence of thrombophilia mutations and their interaction among populations necessitates localized genetic assessments. However, population-based genetic data remains limited for developing effective preventive strategies. Materials and Methods: This cross-sectional observational study was conducted over five years (2020–2024) at a tertiary university hospital in Northern Greece. A total of 2961 individuals aged 18–85 years (mean: 50.5) were registered based on family or medical history of venous thromboembolism (VTE) or clinical symptoms of VTE. The final analysis included 2078 participants comprising 1143 males (55%) and 935 females (45%), who met all the inclusion criteria. Inclusion criteria were absence of acute illness or malignancy, informed consent, and an adequate DNA quantity for genotyping, whereas excluded criteria included incomplete laboratory data, active inflammatory or malignant disease, and cognitive or psychiatric conditions. Peripheral blood samples were collected in 2 mL K₃-EDTA tubes, and genomic DNA was analyzed using real-time polymerase chain reaction (PCR) with melting curve analysis and hybridization probes (LightMix^® in vitro diagnostics, TIB MolBiol, Berlin, Germany). Five thrombophilia-related polymorphisms, Factor V Leiden (F5 G1691A), prothrombin (F2 G20210A), methylenetetrahydrofolate reductase (MTHFR C677T and MTHFR A1298C), and Plasminogen Activator Inhibitor-1 (PAI-1) 4G/5G, were examined for allele and genotype frequencies, Hardy–Weinberg equilibrium testing, pairwise linkage disequilibrium (D′ and r²), and power analysis. For subjects tested for Factor V Leiden (n = 1476), the activated protein C resistance (APC) ratio was additionally evaluated using the ACL TOP 750 analyzer. Results: Allele frequencies were 7.3% for FV Leiden and 3.7% for FII. The PAI-1 allele was distributed at 44%, while the MTHFR (C677T and A1298C) alleles were each present at 33%. Significant linkage disequilibrium was identified between MTHFR (C677T and A1298C) and between MTHFR A1298C and PAI-1. No evolutionary pressure or demographic bias was found in the Hardy–Weinberg equilibrium. The APC ratio demonstrated a high sensitivity (99.2%) and specificity (96.6%), indicating that it may serve as a reliable screening method. Conclusions: Our findings highlight informative patterns in the genetic predisposition to thrombophilia, which may help develop rule-based strategies for implementing thromboprophylaxis guidelines and personalized medical interventions.